External Fixation for Unstable Proximal Humerus Fractures: A Narrative Review

Proximal humerus fractures (PHFs) are common injuries, particularly in the elderly population, and their optimal management remains controversial, especially in unstable fracture patterns. External fixation (EF) represents a minimally invasive treatment option that preserves the fracture hematoma and soft tissues while providing stable fixation. The aim of this narrative review is to summarize and critically appraise the available literature on EF as a treatment option for unstable PHFs. Biomechanical studies indicate that, with an optimized number and configuration of pins, the mechanical strength of EF approaches that of locking plate constructs. Despite heterogeneity in the EF systems used across clinical studies, the underlying principles remain similar. The technique is based on closed reduction and percutaneous fixation, resulting in minimal blood loss, shorter operative time, and a relatively short learning curve. These factors, together with the possibility of performing the procedure in the supine position, make EF particularly suitable for polytrauma patients and elderly individuals requiring minimally invasive surgery. Additional advantages include the ability to initiate early postoperative range of motion and removal of the external fixator in an outpatient setting without anesthesia. Clinical outcomes are generally favorable, particularly in two- and three-part PHFs, whereas results in four-part fractures are less predictable and associated with higher complication rates. The most frequently reported adverse event is pin tract infection, which typically does not require revision surgery and is usually managed successfully with systemic antibiotics. However, comparisons across studies are limited by heterogeneity in study design, fracture patterns, EF constructs, and outcome assessment methods. Further comparative and randomized studies are needed to better define the role of EF in the treatment algorithm of unstable PHFs.